The investigated Mongolian lakes are marked by a large range of trace element concentrations even in very small geographical areas. This work includes the data on major and trace element concentrations along of a series of samples collected in 2009 and 2012. Three geochemical types of lakes have been distinguished within the study area: (1) alkaline soda lakes, (2) chloride lakes with pH < 9.0 and Na-Cl-dominated composition, and (3) sulfate ones with pH < 8. The soda lakes show high concentrations of As, U, F and relatively low salinity
